Use of mitochondrial antioxidant defenses for rescue of cells with a Leber hereditary optic neuropathy-causing mutation

Arch Ophthalmol. 2007 Feb;125(2):268-72. doi: 10.1001/archopht.125.2.268.


Objective: To explore a treatment paradigm for Leber hereditary optic neuropathy (LHON), we augmented mitochondrial antioxidant defenses to rescue cells with the G11778A mutation in mitochondrial DNA.

Methods: Cells homoplasmic for the G11778A mutation in mitochondrial DNA were infected with an adeno-associated viral vector containing the human mitochondrial superoxide dismutase (SOD2) gene. Control cells were infected with an adeno-associated viral (AAV) vector expressing the green fluorescent protein (GFP). Two days later, the high-glucose culture medium was exchanged for a glucose-free medium containing galactose. After 1 or 2 days, cellular production of superoxide was assessed using the fluorescent probe dihydroethidium, and we used TUNEL (terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling) staining to detect apoptotic nuclei. The effect of SOD2 on LHON cell survival was quantitated after 2 or 3 days.

Results: Comparisons of AAV-SOD2-infected LHON cells relative to control cells infected with AAV-green fluorescent protein showed increased expression of mitochondrial SOD that attenuated superoxide-induced fluorescence by 26% (P = .003) and suppressed TUNEL-induced fluorescence by 21% (P = .048) after 2 days of growth in galactose medium, when cell survival increased by 25% (P=.05). After 3 days in galactose medium, SOD2 increased LHON survival by 89% (P = .006) relative to controls.

Conclusion: Protection against mitochondrial oxidative stress may be useful for treatment of LHON.

Clinical relevance: Gene therapy with antioxidant genes may protect patients with LHON against visual loss.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antioxidants / metabolism*
  • Apoptosis
  • Cell Survival
  • Cells, Cultured
  • DNA, Mitochondrial / genetics*
  • Dependovirus / genetics
  • Gene Expression Regulation, Enzymologic / physiology
  • Genetic Therapy*
  • Genetic Vectors
  • Green Fluorescent Proteins / genetics
  • Humans
  • In Situ Nick-End Labeling
  • Microscopy, Fluorescence
  • Mitochondria / metabolism*
  • Optic Atrophy, Hereditary, Leber / enzymology
  • Optic Atrophy, Hereditary, Leber / therapy*
  • Oxidative Stress
  • Plasmids
  • Reactive Oxygen Species / metabolism
  • Superoxide Dismutase / genetics*
  • Superoxides / toxicity
  • Transfection


  • Antioxidants
  • DNA, Mitochondrial
  • Reactive Oxygen Species
  • Superoxides
  • Green Fluorescent Proteins
  • Superoxide Dismutase
  • superoxide dismutase 2